To: J3                                                     J3/22-122
From: Van Snyder
Subject: Enumeration type constructor
Date: 2022-February-20
Reference: 22-007

For documentation purposes, it would be useful to allow the argument to
be an enumerator of the type.

The description of <enumeration-constructor> does not specify the type
of the result.

Edits
-----

[91:25 7.6.2 Enumeration types R771] Replace "scalar-int-expr" with
"scalar-expr".

[91:25+ 7.6.2 Enumeration types R771+] Insert a constraint:

"C7116a (R771) The <scalar-expr> shall be of type integer or the type
        specified by <enumeration-type-spec>."

[91:26 7.6.2p5 Enumeration types] Replace "the" with "a". After
"enumeration type" insert "specified by <enumeration-type-spec>. If the
<scalar-expr> is of type integer, the result is the enumerator".

[91:27 7.6.2p5 Enumeration types] Replace :<scalar-int-expr>" with
<scalar-expr>" twice.

[91:28 7.6.2p5 Enumeration types] Append a sentence: "If the
<scalar-expr> is of enumeration type, the value of the result is the
same as <scalar-expr>."

The revised 7.6.2p5 becomes

     An enumeration constructor returns a value of the enumeration type
     specified by <enumeration-type-spec>. If the <scalar-expr> is of
     type integer, the result is the enumerator whose ordinal position
     is the value of the <scalar-expr>. The <scalar-expr> shall have a
     value that is positive and less than or equal to the number of
     enumerators in the enumeration type?s definition. If the
     <scalar-expr> is of enumeration type, the value of the result is
     the same as <scalar-expr>.